Intelligent control and early warning method for hydraulic system of giant water turbine governor

Abstract

The application discloses a kind of giant water turbine governor hydraulic system intelligent control and early warning method, it includes following steps: S1, the constant temperature control is carried out to the hydraulic oil temperature in oil return tank, so that it is maintained at a temperature constant T;S2: the air leakage of pressure oil tank is early warned;S3: the oil leakage of hydraulic system is early warned;The application maintains the hydraulic system oil temperature at the optimum operating temperature by constant temperature control, reduces the oil leakage of hydraulic system due to deterioration of sealing element from the source, and improves the reliability of the action of speed regulation system, by relevant calculation and the monitoring of the change speed of total oil quantity of hydraulic system, the sensitivity of hydraulic system leakage monitoring is greatly improved, the control logic can effectively solve the phenomenon that the oil level of pressure oil tank is too high and the liquid level of oil return tank is too low due to oil leakage and air leakage during the operation of hydraulic system, and timely early warning signal is sent out, the patent effectively improves the start-up success rate of giant unit.

Description

Technical Field

[0001] This invention relates to the field of governor hydraulic system technology, specifically to an intelligent control and early warning method for a giant water turbine governor hydraulic system. Background Technology

[0002] The start-up, shutdown, and load adjustment of hydro-generator units all require a governor. As a core control component of giant hydro-turbines, the governor typically uses high-pressure turbine oil as its control oil source. A stable and reliable control oil source is provided through the hydraulic system of the governor system. The governor's hydraulic system mainly consists of a pressure oil pump, a pressure oil tank, a return oil tank, an isolation valve, a make-up air valve, a cooler, related pipelines, valves, and control components. The pressure oil tank contains approximately 1 / 3 oil and 2 / 3 gas, with a make-up air valve at the top. The main function of the hydraulic system is to maintain the oil levels in the pressure oil tank and return oil tank at normal values ​​and to keep the pressure in the pressure oil tank within a reasonable range.

[0003] Existing technology controls the start and stop of the oil pump through the oil pressure in the pressure pipeline. When the pressure is lower than the load setting value, the oil pump loads, sending oil from the return oil tank to the pressure oil tank via a pressurized pump to maintain a stable oil pressure. When the pressure in the pressure pipeline and pressure oil tank reaches the unloading setting value, the oil pump unloads and stops pressurizing. For oil level monitoring, existing technology uses a low oil level setting in the return oil tank or pressure oil tank to trigger an alarm; that is, an alarm is triggered when the oil level is below the set value. For oil temperature monitoring, existing technology starts the cooler when the oil temperature is above 45 degrees Celsius and stops the cooler when it is below 35 degrees Celsius. There are no measures to handle low oil temperatures.

[0004] The disadvantages of existing technologies are as follows:

[0005] 1. Existing methods for maintaining pressure in oil tanks do not account for leaks in the oil tanks and related pipelines. In actual production, leaks in the oil tanks have been observed. To maintain the pressure, oil needs to be continuously pumped into the tank, leading to an excessively high oil level in the pressure tank and an excessively low level in the return tank. Frequent manual adjustments are required. However, manually operating the high-pressure ball valves poses a significant equipment safety risk.

[0006] 2. Currently, there is no intelligent hydraulic system for monitoring and warning of oil and air leaks.

[0007] 3. The large temperature fluctuation of the hydraulic system pressure oil is detrimental to the internal sealing elements of the governor; and the low temperature of the turbine oil is detrimental to the reliability of the internal oil-passing components of the governor.

[0008] 4. The existing method of adjusting the liquid level solely by adding / unloading the oil pump often results in situations where all startup conditions are met before the unit starts up, but the hydraulic system starts up at this stage and reports a low oil level in the tank, causing the startup conditions to be unmet and reducing the success rate of unit startup. Startup success rate is a crucial performance indicator for the operation of hydro-generator units. Summary of the Invention

[0009] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an intelligent control and early warning method for the hydraulic system of a giant water turbine governor, so as to solve the problems mentioned in the background art.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by this invention is: an intelligent control and early warning method for the hydraulic system of a giant water turbine governor, which includes the following steps:

[0011] S1. The temperature of the hydraulic oil in the return oil tank is kept constant at a fixed temperature T.

[0012] S2: Provides early warning of air leakage in pressure oil tanks;

[0013] S3: Provides early warning of oil leakage in the hydraulic system.

[0014] Preferably, the temperature setpoint T in S1 is 35°C.

[0015] Preferably, the specific temperature control method for S1 is as follows:

[0016] S1.1 If the oil temperature in the return oil tank is below 35℃, the heater located at the bottom of the return oil tank will be automatically started; if the oil temperature in the return oil tank is above 35℃, the heater will stop heating and the cooler will be put into operation for cooling.

[0017] S1.2 When the heater is heating and the oil pump is not running, turn on the micro circulation pump to maintain a small amount of oil circulation in the return oil tank.

[0018] Preferably, step S2 specifically includes the following steps:

[0019] S2.1, Setting H g H is the high oil level alarm value for the pressure tank. d The low oil level alarm value for the pressure tank; then H b The target oil level for the pressure tank is (H). g -H d ) / 2+H d ;

[0020] S2.2 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the pressure in the pressure tank is higher than P1 and the oil level in the pressure tank is ≥ H... bIf the pressure does not reach P2, the oil pump will stop loading. If the pressure does not reach P2, it is determined that there is a slight air leak in the oil tank. A warning signal will be issued and the air supply valve on the top of the oil tank will be opened to supply air until the pressure in the oil tank is ≥ P2.

[0021] S2.3 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the oil level in the pressure tank is ≥ H... b If the pressure in the oil tank is not greater than P1, it is determined that there is a serious air leak in the oil tank. The oil pump continues to load until the oil pressure is greater than P1, and at the same time, a warning signal is issued to notify the operators to deal with it immediately.

[0022] S2.4 When the pressure in the pressure tank is lower than P1, start the pressure pump to load. When the pressure in the pressure tank is higher than P2, if the oil level in the pressure tank is still not greater than or equal to H... b If the problem occurs, the oil pump will stop loading. At the same time, if it is determined that the air supply valve is not closed tightly or the oil level gauge of the pressure tank is malfunctioning, an early warning signal will be issued to notify the operators to handle the situation on site.

[0023] Preferably, P1 is 6.1 MPa and P2 is 6.3 MPa.

[0024] Preferably, step S3 specifically includes the following steps:

[0025] S3.1, Setting V g V is the bottom area of ​​the pressure oil tank; u h is the bottom area of ​​the return oil tank. g The high oil level alarm value for the return tank; h d The low fuel level alarm value is the value for the return fuel tank; h b The reference oil level in the return tank has the following value: (h) g -h d ) / 2+h d ;

[0026] S3.2 After the governor's hydraulic system is put into operation, adjust the hydraulic system oil temperature to the set value T. When the pressure pump is loaded, the oil level in the pressure tank must be adjusted to the target oil level H. b Under normal circumstances, as long as there is no leakage in the hydraulic system oil, the pressure oil tank level should be H. b At that time, the corresponding oil level in the return tank is h. b ;

[0027] S3.3 When the actual oil level in the return tank h < h b Furthermore, the actual oil level H in the pressure tank is different from the target oil level H in the pressure tank. b The difference satisfies the formula: (H b -H) / H b If the percentage is ≥1%, it is determined that there is an oil leak in the hydraulic system, and an early warning signal is issued to notify the operators to handle the situation immediately.

[0028] The beneficial effects of this invention are:

[0029] 1. This invention maintains the hydraulic system oil temperature at the optimal operating temperature through constant temperature control, reducing oil leakage caused by seal deterioration at the source and improving the reliability of the speed control system. Through relevant calculations and monitoring of the rate of change of the total hydraulic oil volume, the sensitivity of hydraulic system leakage detection is greatly improved. Its control logic can effectively solve the problems of excessively high oil level in the pressure tank and excessively low oil level in the return tank caused by oil and air leakage during the operation of the hydraulic system, and issue early warning signals in a timely manner. This patent effectively improves the start-up success rate of giant units.

[0030] 2. When the hydraulic system is first started, the pressure pump pressurizes the oil from the return oil tank to the pressure oil tank. Before the pressure pump starts, the connection between the return oil tank and the pressure oil tank is empty, and the pressure in the pressure oil tank is also low. Therefore, the oil level in the return oil tank will drop slightly after the hydraulic system starts. If the oil level in the return oil tank is just near the alarm level before starting, but has not yet reached the alarm value, the hydraulic system will report a low return oil level, indicating that the unit's start-up conditions are not met. This can lead to a situation where all parameters are normal before the unit starts, but an alarm is triggered upon startup, resulting in a large-scale unit startup failure. This invention provides early warnings for air leakage in the pressure oil tank and oil leakage in the hydraulic system, especially the target oil level value (H) in the pressure oil tank. g -H d ) / 2+H d And the reference oil level in the return tank (h) g -h d ) / 2+h d The investment ensures that the failure to start up giant generator units will no longer occur. Attached Figure Description

[0031] Figure 1 This is a trend chart of the operating data of the governor hydraulic system before using the method of the present invention;

[0032] Figure 2 This is a trend chart showing the change in operating data of the governor hydraulic system after using the method of the present invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] A method for intelligent control and early warning of the hydraulic system of a giant water turbine governor, comprising the following steps:

[0035] S1. The temperature of the hydraulic oil in the return oil tank is kept constant at a fixed temperature T.

[0036] S2: Provides early warning of air leakage in pressure oil tanks;

[0037] S3: Provides early warning of oil leakage in the hydraulic system.

[0038] Preferably, the temperature setpoint T in S1 is 35°C.

[0039] Preferably, the specific temperature control method for S1 is as follows:

[0040] S1.1 If the oil temperature in the return oil tank is below 35℃, the heater located at the bottom of the return oil tank will be automatically started; if the oil temperature in the return oil tank is above 35℃, the heater will stop heating and the cooler will be put into operation for cooling.

[0041] S1.2 When the heater is heating and the oil pump is not running, turn on the micro circulation pump to maintain a small amount of oil circulation in the return oil tank.

[0042] In this embodiment, multiple small heaters can be added to the bottom of the return oil tank. Since the heaters are activated when the temperature is below 35°C (around 34°C), the activation temperature difference can be appropriately widened to avoid excessively frequent heater activation and deactivation. Only slight heating of the oil is needed; therefore, the focus is not on the power of a single heater, but on their small size and number to achieve precise temperature control. Additionally, the micro-circulation pump maintains a small amount of oil circulation in the return oil tank while the heaters are heating and the pressure pump is not running, ensuring accurate temperature measurement. If the pressure pump is running, it can drive the oil circulation itself, eliminating the need to activate the micro-circulation pump. Furthermore, four temperature sensors are installed inside the return oil tank. The average value is used as the output temperature of the return oil tank to control the heater's activation and deactivation, and the cooler's activation and deactivation. When one temperature sensor shows a significant difference (above 4°C) from the other three, the average value of the other three sensors is used as the oil temperature control value, and a temperature sensor fault signal is simultaneously issued. Finally, because the speed governor and hydraulic system are all located inside the factory building, and the factory building is equipped with central air conditioning, there will be no situation where the temperature in the return oil tank exceeds 35°C when the unit is shut down due to excessively high summer temperatures (when the unit is shut down, the hydraulic system is in a stopped state, there is no heat source generated, but at the same time there is no cooling water, and the cooler cannot work; the return oil tank temperature is mainly affected by the ambient temperature).

[0043] The aforementioned constant temperature control ensures that the oil temperature of the governor's hydraulic system is always kept at the optimal level, greatly improving the reliability of the governor's operation and the service life of the sealing elements, and fundamentally reducing the probability of hydraulic system leakage.

[0044] Preferably, step S2 specifically includes the following steps:

[0045] S2.1, Setting H g H is the high oil level alarm value for the pressure tank. d The low oil level alarm value for the pressure tank; then H b The target oil level for the pressure tank is (H). g -H d ) / 2+H d ;

[0046] S2.2 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the pressure in the pressure tank is higher than P1 and the oil level in the pressure tank is ≥ H... b If the pressure does not reach P2, the oil pump will stop loading. If the pressure does not reach P2, it is determined that there is a slight air leak in the oil tank. A warning signal will be issued and the air supply valve on the top of the oil tank will be opened to supply air until the pressure in the oil tank is ≥ P2.

[0047] S2.3 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the oil level in the pressure tank is ≥ H... b If the pressure in the oil tank is not greater than P1, it is determined that there is a serious air leak in the oil tank. The oil pump continues to load until the oil pressure is greater than P1, and at the same time, a warning signal is issued to notify the operators to deal with it immediately.

[0048] S2.4 When the pressure in the pressure tank is lower than P1, start the pressure pump to load. When the pressure in the pressure tank is higher than P2, if the oil level in the pressure tank is still not greater than or equal to H... b If the problem occurs, the oil pump will stop loading. At the same time, if it is determined that the air supply valve is not closed tightly or the oil level gauge of the pressure tank is malfunctioning, an early warning signal will be issued to notify the operators to handle the situation on site.

[0049] Preferably, P1 is 6.1 MPa and P2 is 6.3 MPa.

[0050] Preferably, step S3 specifically includes the following steps:

[0051] S3.1, Setting V g V is the bottom area of ​​the pressure oil tank; u h is the bottom area of ​​the return oil tank. g The high oil level alarm value for the return tank; h d The low fuel level alarm value is the value for the return fuel tank; h b The reference oil level in the return tank has the following value: (h) g -h d ) / 2+h d ;

[0052] S3.2 After the governor's hydraulic system is put into operation, adjust the hydraulic system oil temperature to the set value T. When the pressure pump is loaded, the oil level in the pressure tank must be adjusted to the target oil level H. bUnder normal circumstances, as long as there is no leakage in the hydraulic system oil, the pressure oil tank level should be H. b At that time, the corresponding oil level in the return tank is h. b ;

[0053] S3.3 When the actual oil level in the return tank h < h b Furthermore, the actual oil level H in the pressure tank is different from the target oil level H in the pressure tank. b The difference satisfies the formula: (H b -H) / H b When the level is ≥1%, it is determined that there is an oil leak in the hydraulic system, and a warning signal is issued to notify the operators to handle it immediately. Here, 1% is selected, which is approximately 20mm based on the actual oil level. The error of one division of a float-type level gauge is generally within 10mm, so using 20mm as the level alarm value is more sensitive and can avoid normal errors.

[0054] In the above technical solution, the oil volume of the speed governor and hydraulic system is mainly concentrated in the return oil tank and the pressure oil tank. Since the return oil tank of the hydraulic system is temperature-controlled, the influence of oil temperature on oil volume can be disregarded. During the operation of the hydraulic system, the loading frequency is actually very high, occurring every few minutes, allowing the oil in the return oil tank to quickly exchange with the oil in the pressure oil tank. Soon, the oil temperatures in the return oil tank and the pressure oil tank become identical; therefore, the overall oil temperature can be considered a constant value T.

[0055] The following comparison of the governor hydraulic system operating data before and after using the method of the present invention further illustrates the beneficial effects of the method of the present invention:

[0056] Table 1. Operating data of the governor hydraulic system using traditional methods.

[0057]

[0058] Table 2. Operating data of the governor hydraulic system after using the method of the present invention. As can be seen from the table above, after implementing the method of this invention, when the pressure of the pressure oil tank is consistent, the corresponding oil level in the return oil tank and the oil level in the pressure oil tank are also consistent with each other. Compared with the traditional method, its various operating data are more stable.

[0059] in addition Figure 1 This is a trend chart of the operating data of the governor hydraulic system before using the method of the present invention. Figure 2 This is a trend chart of the operating data of the governor hydraulic system after using the method of the present invention. Figure 2 It can be more intuitively seen that the operating data of the speed governor hydraulic system corresponding to the method of the present invention is more stable, and its variation range is smaller. Figure 1The corresponding governor hydraulic system operating data showed a large fluctuation range; therefore, it is indicated that after the intervention of the method of the present invention, the governor hydraulic system operating data became more stable.

[0060] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for intelligent control and early warning of a hydraulic system of a giant water turbine governor, characterized in that: It includes the following steps: S1. The temperature of the hydraulic oil in the return oil tank is kept constant at a fixed temperature T. S2: Provides early warning of air leakage in pressure oil tanks; S3: Provides early warning of oil leakage in the hydraulic system; Step S2 specifically includes the following steps: S2.1, Setting H g H is the high oil level alarm value for the pressure oil tank. d The low oil level alarm value for the pressure oil tank; then H b The target oil level for the pressure tank is (H). g -H d ) / 2+H d ; S2.2 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the pressure in the pressure tank is higher than P1 and the oil level in the pressure tank is ≥ H... b If the pressure does not reach P2, the oil pump will stop loading. If the pressure does not reach P2, it is determined that there is a slight air leak in the oil tank. A warning signal will be issued and the air supply valve on the top of the oil tank will be opened to supply air until the pressure in the oil tank is ≥ P2. S2.3 When the pressure in the pressure tank is lower than P1, start the pressure pump to load; when the oil level in the pressure tank is ≥ H... b If the pressure in the oil tank is not greater than P1, it is determined that there is a serious air leak in the oil tank. The oil pump continues to load until the oil pressure is greater than P1, and at the same time, a warning signal is issued to notify the operators to deal with it immediately. S2.4 When the pressure in the pressure tank is lower than P1, start the pressure pump to load. When the pressure in the pressure tank is higher than P2, if the oil level in the pressure tank is still not greater than or equal to H... b If the oil pressure pump stops loading, and the system determines that the air supply valve is not closed tightly or the oil level gauge of the pressure tank is malfunctioning, it will issue a warning signal and notify the operators to handle the situation on-site. The P1 is 6.1 MPa and the P2 is 6.3 MPa; Step S3 specifically includes the following steps: S3.1, Setting V g V is the bottom area of ​​the pressure oil tank; u h is the bottom area of ​​the return oil tank. g The high oil level alarm value for the return tank; h d The low oil level alarm value for the return tank; h b The reference oil level in the return tank has the following value: (h) g -h d ) / 2+h d ; S3.2 After the governor's hydraulic system is put into operation, adjust the hydraulic system oil temperature to the set value T. When the pressure pump is loaded, the oil level in the pressure tank must be adjusted to the target oil level H. b Under normal circumstances, as long as there is no leakage in the hydraulic system oil, the pressure oil tank level should be H. b At that time, the corresponding oil level in the return tank is h. b ; S3.3 When the actual oil level in the return tank h < h b Furthermore, the actual oil level H in the pressure tank is different from the target oil level H in the pressure tank. b The difference satisfies the formula: (H b -H) / H b If the percentage is ≥1%, it is determined that there is an oil leak in the hydraulic system, and an early warning signal is issued to notify the operators to handle the situation immediately.

2. The intelligent control and early warning method for the hydraulic system of the speed regulator of a giant water turbine according to claim 1, characterized in that: The temperature setpoint T in S1 is 35℃.

3. The intelligent control and early warning method for the hydraulic system of the speed regulator of a giant water turbine according to claim 2, characterized in that: The specific temperature control method for S1 is as follows: S1.1 If the oil temperature in the return oil tank is below 35℃, the heater located at the bottom of the return oil tank will be automatically started; if the oil temperature in the return oil tank is above 35℃, the heater will stop heating and the cooler will be put into operation for cooling. S1.2 When the heater is heating and the oil pump is not running, turn on the micro circulation pump to maintain a small amount of oil circulation in the return oil tank.

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